The invention is based on a device for operating a gas discharge lamp of the type having a voltage transformer which transforms the direct voltage of an energy source into a predetermined output voltage, and a bridge circuit connected with the output of the transformer, with the lamp being disposed in the diagonal of the bridge. The technical journal ELEKTOR, No. 6, 1988, "Leuchtstofflampen-Elektronik" [Electronics for Fluorescent Lamps], pages 14-19, discloses an electronic input device for operating a gas discharge lamp. The input device includes a voltage transformer which converts a given input voltage, in this case, for example, the mains voltage, into a predetermined alternating output voltage. A bridge circuit configured as a half-bridge is connected with the output of the voltage transformer and with the gas discharge lamp being disposed in the diagonal of the half-bridge. The voltage transformer includes a transformer that ensures a potential separation between the mains voltage at the input and the bridge circuit. Due to an unavoidable stray capacitance between the gas discharge lamp and components, such as, for example, a light fixture disposed in the vicinity of the lamp, an average potential of zero volts will be established between the lamp and the components.
Other suitable voltage transformers for operating a gas discharge lamp are known from the textbook by U. Tietze and Ch. Schenk, entitled "Halbleiter-Schaltungstechnik" [Semiconductor Circuit Technology], 6th Edition, 1983, published by Springer-Verlag, pages 545-552. Described are basic circuits of voltage transformers such as, for example, an up-transformer and inverting transformers without potential separation as well as single-ended flyback converters, single-ended flow converters and push-pull converters with potential separation during the transformation.
When operating a gas discharge lamp, care must be taken that no direct current component develops that flows through the lamp to avoid ion migration. Already in the year 1938, the textbook by Dr. W. Uyterhoeven, entitled "Elektrische Gasentladungslampen" [Electrical Gas Discharge Lamps], published by Springer-Verlag, 1938, pages 249-252, pointed out that the service life of gas discharge lamps, demonstrated by the example of sodium high pressure lamps, is limited, among others, by the interaction of the sodium ions with the lamp body.